Technical Field
The technical field relates to the fabrication of integrated circuits, particularly to methods and devices for pre-cleaning a wafer or substrate surface.
Background Information
Integrated circuit fabrication often involves formation of one or more material layers on a substrate (also referred to as a “wafer”) surface. These material layers can include, for example, mono-crystalline, polycrystalline, or other amorphous material layers. Formation of the material layers can be achieved using various thin film deposition techniques, including various physical deposition techniques, e.g., physical sputtering, or chemical deposition techniques, e.g. chemical vapor deposition (CVD), atomic layer deposition, or epitaxial deposition. For example, mono-crystalline material formation on a substrate surface can be performed using an epitaxial deposition process, such as for formation of mono-crystalline semiconductor materials (e.g., mon-crystalline silicon).
The presence of an intervening material (e.g., a native oxide layer, such as a silicon oxide material layer on a silicon wafer) on the wafer surface may interfere with formation of a desired material layer over the wafer surface. For example, the intervening material may cause introduction of an increased number of defects in the structure of the desired material layer or may adversely affect an electrical performance of the desired material layer. In some embodiments, an intervening material such as a native oxide material may form on a wafer surface due to exposure of the wafer to oxygen during the integrated circuit fabrication process, e.g., exposure to ambient air during transfer of the substrate between fabrication systems, or residual oxidizing agents within fabrication systems. Accordingly, fabrication techniques and systems to remove native oxide from a wafer may be desirable to facilitate subsequent deposition on a wafer surface.